I would never subscribe to any form of exclusion from treatment under the NHS, its a slippy slope that leads to much wider exclusion of other treatments over time. I'd prefer education .
I completely agree with your point about education, but it's worth remembering that rationing and prioritisation of NHS services, including those for alcohol-related issues, has been going on for years and is a completely normalised part of modern medical practice - look at weight/BMI requirements for stuff like orthopaedic or heart surgery for example
One of the guys who used to drink in my local died a couple of years back, he was denied the chance of a liver transplant because the doctors felt he wouldn't be a good recipient due to his lifestyle (ie he would simply just drink his new liver into oblivion too). Knowing the guy I have to say the medics were right, he was a lost cause. The donated liver presumably went to a more deserving recipient, and a jolly good thing too.